In the context of the Hadley cells, we equate \(\)  in (REF ) with the cells' ascending edge on the grounds that ascent out of the viscous boundary layer there transmits the local planetary angular momentum, \(M_{p}()\) , to the comparatively inviscid free troposphere [1]}, [2]}. This neglects the finite width of the ascent branch [3]}, [4]}, but in principle one could compute an effective ascent latitude by averaging the planetary angular momentum over the full extent of the ascending branch, perhaps weighting by the vertical velocity out of the boundary layer at each latitude.
